VB.6的环境下一阶、二阶、三阶和四阶导数的数值算法

单边裂纹梁的前四阶频率计算，完成以后进行系数的计算，然后得到振型，并画出图片-Unilateral cracked beam of the first four frequency bands calculated after the completion of the coefficient calculation, and then get mode shapes, and draw pictures

时间二阶、空间四阶无边界条件声波波场模拟,提供了两个模型，均匀半空间和两层层状介质模型，并附有动画-time two orders,space four orders,no boundary conditions,sonic wave-field simulation

用于计算非线性介质中的四阶色散,带图像，改相关参数就可以计算(it is used for calculating the four-order dispersion of nonliear mediums)